History of waste tank 10, 1955 through 1974

Tank 10 was placed in service as a receiver for high heat waste (HW) on December 15, 1955. Twelve years later, in January and February 1967, the supernate was decanted and the sludge was removed. During the sludge removal operation, a spill of approximately 250 Ci occurred. The tank was then used as a receiver and cooler for hot evaporator bottoms including usage as the first stage of a two-stage transfer system (TA 2-650). The resulting salt crystals were left in storage in tank 10. Twenty-one cooling coils have leaked with the last fourteen occurring since sludge removal and with no flow of chromate-inhibited cooling water through them. Leakage from the tank into the annulus was discovered in July 1959. However, no leaksites have been found. The maximum annulus liquid depth measured was 2.5 inches but the solid salt residue had built up to about 2 inches by February 1972. Inspections have been made of the annulus and the tank interior both visually and with an optical periscope. Analytical samples have been taken of the sludge, supernate, vapor, and annulus salt. Bedrock and steel specimens were tested in the tank to determine the long term waste/corrosion effects on them. Top-to-bottom profiles of radiation and temperature have been obtained and measurements have been made of gradual roof deflection under increasing load from salt buildup on the cooling coils. Also, tests of salt loading on simulated vertical coils have been made (DPSPU 70-11-2). Several equipment modifications and various equipment repairs were made